Engine starter



Dec. 23, 1924. 1,520,468

B. D. GILSON ENGINE STARTER Filed Sept. 21, 1921 INVENTUR E; l m5 HTTURNBY.

' such engines,

Patented Dec. 23, 1924.

warren srarss BERT D. GILSON, OF CHICAGO, ILLINOIS.

ENGINE Application filed September To all 20/10/11 it may concern:

Be it known that 1. Bear I). (iILSON, a citizen of the United 'States, residing at Chicago, in the county of Cook and State of Illinois. have invented new and useful linprovements in Engine Starters, of which the following is a specification.

This invention has relation to engines. and ithas particular reference to starting means for such engines. Some engines are not entirely self starting, and the engines of another class will usually not start at all until some outside source of power is applied for starting purposes. A steam engine, or at least a one cylinder engine, often comes to a stop on the dead center and some external power must be applied to start it over the dead center. Internal combustion engines in most cases will not start without cranking or the application of some such equivalent application of out-side power.

The object of the present invention is the provision of improved means for starting and structures illustrative of my invention are hereinafter fully described and illustrated in the appended drawing, of which:

Fig. 1 is a side elevation of an engine embodying the invention,

F ig. 2 shows, on a very much larger scale the starting mechanism of my invention in its relation to co-operating parts of the engine,

Fig. 3 is a similar view, in which a modification is embodied. and

Fig. 4 is a fragmental view showing parts of the structure of Fig. 1.

The engine of Fig. 1 is of the internal combustion type, having on its crank shaft 1 a fly wheel 2, and on the periphery of this wheel is provided a toothed portion 3, which may be detachable or part of the wheel, as desired. Suitably located on the engine casting, or the crank case. is an electric motor 4, from which extends a shaft 5 parallel with the engine crank shaft. on the motor shaft 5 is mounted a toothed pinion 6, through the medium of whi h rotations of the said motor are communicated to the fly Wheel for the purpose of starting the engine.

Referring now to Fig. 2 it is seen that the motor shaft 5 supports rigid collars 7 and 8, in spaced relation, and that a sleeve 9 is mounted on the shaft between the said STARTER.

21, 1921. Serial No. 502,146.

collars. Concentric with the shaft and sleeve is a cylindrical housing 10. which may be suitably secured to the sleeve, as by a plurality of pins or screws 12, or it may he made a part of the sleeve. In any case, for the purpose of this description it does form part of the sleeve. and it is provided with internal screw threads 10*. The aforenamed pinion 6 is slidably fitted on the sleeve. and it is provided with screw threads (3". meshing with the screw threads of the housing.

The instrumentalities so far described coact to start the engine in the following manner. The motor, motor shaft. sleeve and housing all start together when the circuit through the motor is closed, and they gain speed instantly. But the pinion 6 is free to rotate on the sleeve, and it is by its i11- ertia opposed to a change of condition. It does not start at once, and it gains speed more slowly. Yet it cannot remain stationary because of the intermeshing screw threads 6, 10. and as a consequence it is forced to advance axially on the sleeve.

The face (3 of the pinion is positioned very close to the edge of the fly wheel gear 3, into engagement with which it new advances, and as soon as it touches this gear it is held against rotation. It must now continue to advance until its face 6 strikes the shoulder portion 7 of the collar 7, whereupon it becomes locked for positive rotation by and with the motor shaft, and as a consequence commences to turn the fly wheel to start the engine. The moment the engine is started it is found that the fly wheel commences to increase the speed of the pinion, with the result that the latter rotates faster than the motor shaft and commences to return into the housing. finally again to become disengaged from the fly wheel ear. If the motor stops before the return of the pinion, the result will only be to increase the speed of return of the pinion.

An electric motor is a very flexible apparatus, and it will stand much abuse. Yet it is well to introduce some sort of cushioning meansto absorb the shock when the pinion strikes the collar 7 and meets the sudden resistance of the fly wheel with its engine connections. the shape of a suitable buffer element 25, see Fig. 3, which is capable of some compression. Or it may be accomplished by the interposition of yielding driving con- Such means may take.

nections, as shown in Fig. 2. Within the sleeve .9 is an annular space, in ,which a resilient member 13 is seated, and the latter is made with projecting ends 13, 13*, which in turn lodge in a notch T of the collar 7 and 9 of the sleeve 9, as bestindicated in Fig. 4. Having introduced this resilient member it is seen that rotationsof the motor shaft are transmitted through said member to the sleeve, which otherwise is free to rotate 011 the shaft, and that the desired cushioning effect is obtained. It is important to note that no screws or other fastening means are employed in connection with the resilient member 13, which is held firmly in position in the notches referred to, and which is of great strength, having no loops or eyes capable of breaking.

The housing 26, of the structure of Fig. 3, is rigid on the motor shaft 27, and the pinion 28 may ride directly on this shaft, otherwise the structure may be exactly like the device of Figs. 1 and 2. The resilient member 25 may well take some other-form,

so long as it performs the function of sorbing the shock.

Other starters are made utilizing the old princi le of advancing a pinion into mesh with t e engine fly wheel upon starting the motor, as described, but in such starters the mistake has been made of mounting the pinion on a screw, in which case the perforation through the pinion is provided with corresponding screw threads. The closer to the axis of the shaft the screw threads, by which the pinion is advanced, are placed, the greater is also the frictional resistance between the screw and pinion. For this reason it will be observed that additional means, such as counterweights, have been added to the pinion of such devices in order I to delay the rotation of the pinion and thereby to attain the required advance movement.

In the structures of my invention the screw threads have been brought far enough away from the axis of the motor shaft to reduce the frictional resistance sufliciently to be safely overbalanced by the inertia of the pinion. Due to this construction it is found that no counterweight or other re tarding means is required in the structure of my invention.

- A yielding driving connection between the drive shaft and the sleeve is old in the art, and the novelty of my structure resides in enclosing this yielding member within the sleeve. Another novelty of my struc ture is the feature of enclosing the pinion when it is not projected into engagement with the fly wheel incident to starting the engine. The whole device is very simple; its rylindrical outline gives it a pleasing compact and trim appearance, and it is noticed that no part projects, but that it is perfectly smooth and incapable of catching the operators dress.

In some small automobiles very little room is provided, into which to mount a starting mechanism, and for such small machines my device is particularly adapted In larger automobiles much more room is found, and the requirements less exacting. I have shown the screw threads 6 cut directly into the outer periphery of the pinion 6, but I can, of course, in larger machines, or wherever there is sufficient room out these threads on a separate piece and attach this piere to the pinion. Such are mechanical .modifications, but the principle remains,

namely, that the screw threads must rise from the periphery of the pinion in order to be far enough removed to reduce the axial friction, as hereinb'efore explained.

I claim:

1. The combination with an engine and a starting motor, of apinion on the motor 7 shaft provided with screw, threads rising from the outer periphery of the pinion teeth, and a housing covering the pinion and 7 having internal screw threads in mesh with the pinion threads, whereby the pinion is caused to advance along the shaft upon starting the motor and housing.

2. The combination with an engine and a starting motor, of a sleeve on "the motor shaft, a pinion movable on said shaft and provided with screw threads rising from the outer periphery of said pinion, a cylindrical housing rigid with said sleeve and having internal screw threads meshing with the pinion threads for the-purpose of adthreads in mesh with screw threads risingf from the outer periphery of said pinion, and a resilient member within said sleeve for absorbing the shock incident to such engagement.

In testimony whereof I have hereunto allixed my signature.

BERT I). G] LSON. 

